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动态 (4985)
Miss Chen
2018年06月04日
Miss Chen
Description: This perennial wildflower is 1½–3' tall and unbranched or sparingly branched. The stout central stem is erect, medium green, hairless, and terete. Basal leaves are usually cordate or oval-cordate with long petioles; sometimes they are odd-pinnate with 2 small lateral leaflets and a large terminal leaflet. The cauline leaves occur in opposite pairs along the stem and they are odd-pinnate with 3-7 leaflets. Each cauline leaf is up to 8" long and 4" across. The leaflets are more or less ovate in shape; the terminal leaflet is larger than than the lateral leaflets. The leaflets are medium green, hairless, and smooth to slightly dentate along their margins. Each cauline leaf is sessile at the base, or it has a short petiole. The central stem terminates in a short dense panicle of flowers that becomes more elongated with age. Much smaller panicles of flowers may develop from the axils of the upper leaves. Each flower has a slender funnelform corolla with 5 spreading lobes; this corolla is white to light pink and about ½–¾" long. Exerted from each corolla, there are 3 stamens and a slender style. At the base of the flower, there is a green calyx that is much shorter than the corolla. The blooming period occurs from late spring to early summer and lasts about a month. Each flower has a single-celled ovary that produces a single achene. Each achene has a tuft of plume-like hairs; the achenes are distributed in part by the wind. The root system is fibrous and its produces occasional rhizomes or stolons. Sometimes small colonies of plants develop from the rhizomes or stolons. Cultivation: The preference is light shade to partial sun, consistently moist conditions, and fertile soil with abundant organic matter. The foliage is rarely bothered by disease or insects. Range & Habitat: The native Large-Flowered Valerian is occasional in extreme east-central, southeast, and southern Illinois; elsewhere in the state, it is largely absent (see Distribution Map). Illinois lies at the western range-limit for this species. Habitats include floodplain woodlands along streams or rivers, shaded ravines, and bottoms of rocky canyons. This species is found in high quality habitats that are moist and shady.
Faunal Associations: Information about floral-faunal relationships for this species is very limited. The long slender corollas suggests that the flowers are pollinated by bumblebees, butterflies, Sphinx moths, and possibly hummingbirds. The nectar of the flowers is inaccessible to most insects with short mouthparts. Photographic Location: The wooded bottom of a sandstone canyon at The Portland Arch in west-central Indiana. In the flowerhead close-up, most of the flowers are still in the bud stage. Comments: This is the showiest Valeriana sp. in Illinois. Its flowers exceed ½" in length, while the flowers of other native and naturalized Valeriana spp. are less than ½" in length. Large-Flowered Valerian should be cultivated more often. Sometimes, this species is called Pink-Flowered Valerian.
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Miss Chen
2018年06月04日
Miss Chen
Description: This herbaceous perennial plant is about 1-2' tall. In mature plants, the central stem divides into 2 or 3 side stems, while immature plants usually remain undivided. The upper portion of each plant tends to nod downward because of the weight of the leaves and flowers. The terete stems are glabrous and glaucous; they are light green or pale reddish green. The alternate leaves are up to 6" long and 2" across. They are oblong-ovate to elliptic, smooth along their margins, and parallel-veined. The base of each leaf is perfoliate – it completely surrounds the stem. The upper surface of each leaf is pale green to green and glabrous, while the lower surface is white to greenish white and finely short-pubescent (canescent). In mature plants, each side stem terminates with a single flower that has an elongated bell-like shape. The flowers are about 1-2" long and they hang downward from slender pedicels about 1" long. The pedicels are similar to the stems, except they are more slender. Each flower consists of 6 pale yellow to yellow tepals, 6 stamens, and a pistil with a tripartite style. The slender tepals are slightly twisted and greenish toward the base of the flower, while their interior surface is smooth and hairless. The yellow anthers of the stamens are large and elongated, but they remain mostly hidden by the tepals. The blooming period occurs during the mid-spring and lasts about 2 weeks. The flowers are slightly fragrant. Each flower is replaced by a 3-celled seed capsule that is obovoid in shape with 3 rounded lobes and a rounded tip; each cell of this capsule contains several seeds. The root system is rhizomatous, from which vegetative offsets are often produced. This plant occasionally forms colonies.
Cultivation: The preference is dappled sunlight during the spring and light shade during the summer. The soil should be moderately moist and loamy with a layer of decaying leaves. It is best to locate this plant underneath a deciduous tree that does not cast heavy shade during the summer. It is easier to start new plants from divisions, rather than by seeds. Range & Habitat: The native Large-Flowered Bellwort occurs occasionally in most areas of Illinois, except for a few counties in southern part of the state (see Distribution Map). Populations of this wildflower have declined somewhat because of deer-browsing, habitat destruction, invasion of various non-native shrubs, and invasion of Garlic Mustard (Alliaria petiolata). Habitats include mesic deciduous woodlands, wooded slopes, large river banks in wooded areas, and edges of shady seeps. The presence of this plant in a deciduous woodlands is an indication that much of the original ground flora is still intact.
Faunal Associations: Bumblebees, mason bees (Osmia spp.), Halictid bees (Halictus spp., Lasioglossum spp.), and Andrenid bees (Andrena spp.) suck nectar or collect pollen from the flowers. The seeds are distributed by ants because of their attached elaiosomes (small food bodies). The foliage is heavily grazed by deer; this species declines in abundance when there is an overpopulation of deer in wooded areas. The foliage is probably vulnerable to other mammalian herbivores as well. Photographic Location: A deciduous woodland along a river bank at Allerton Park in Piatt County, Illinois.
Comments: The flowers are rather shy and often hide behind the leaves. The foliage of Large-Flowered Bellwort (Uvularia grandiflora) is attractive and resembles the foliage of Polygonatum commutatum (Smooth Solomon's Seal). However, the leaves of the latter species are sessile or clasping, while the leaves of Large-Flowered Bellwort are perfoliate. The only other species in this genus that occurs in Illinois (the southern part only) is Uvularia sessilifolia (Sessile-Leaved Bellwort). As the name suggests, the leaves of this species are sessile, rather than perfoliate, and its flowers are a little smaller than those of Large-Flowered Bellwort. The 3-celled seed capsules of this species are sharply lobed (even winged), while the corresponding lobes of Large-Flowered Bellwort are well-rounded. Another species in this genus, Uvularia perfoliata (Perfoliate Bellwort), occurs in areas to the east of Illinois. This species has perfoliate leaves like Large-Flowered Bellwort. However, its seed capsules are truncated at their tips and its tepals have glandular hairs on the interior surface. Large-Flowered Bellwort has seed capsules with rounded tips and its tepals are smooth on the interior surface.
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Miss Chen
2018年06月04日
Miss Chen
Description: This perennial wildflower is 2–3½' tall and unbranched. The central stem is light green, terete, and pubescent. Pairs of opposite leaves occur at intervals along this stem; each pair of leaves rotates 90º from the orientation of the preceding pair of leaves. The leaves are up to 8" long and 4" across, ovate or ovate-oblong in shape, and smooth to slightly undulate along their margins. All or most leaves have winged bases that surround the stem and merge with the bases of the leaves on the opposite side. The upper surfaces of the leaves are dull green and hairless to slightly pubescent, while their lower surfaces are whitish green and covered with short fine pubescence. Sessile clusters of 1-5 flowers occur in the axils of the leaves. Each flower has a narrow tubular corolla (about ½" long); usually this corolla is reddish brown (less often, it is more green or yellow). The corolla has 5 lobes that are short and well-rounded. The 5 sepals are about the same length as the corolla and linear in shape; they are light green to dark reddish brown. At the base of each flower, there is a 3-celled ovary that is green and hairy, and a pair of linear stipules that resemble the sepals. Within the corolla, there are 5 stamens and a single style with a knobby green stigma. The blooming period occurs from late spring to mid-summer and lasts about a month. Each flower is replaced by a dry drupe about 1/3" (8 mm.) across that is globoid in shape and becomes orange at maturity. Inside each drupe, there are 3 black nutlets; these nutlets are 3-angled and oblongoid in shape. The root system consists of a taproot. This wildflower spreads by reseeding itself. Cultivation: The preference is light shade to dappled sunlight, mesic to slightly dry conditions, and a loamy or rocky soil with abundant organic matter. Range & Habitat: Late Horse Gentian is occasional in central and northern Illinois, becoming uncommon or absent in southern areas of the state (see Distribution Map). This is a native wildflower. Habitats include upland deciduous woodlands, rocky wooded slopes, thinly wooded bluffs, oak savannas, and limestone glades.
Faunal Associations: The nectar of the flowers attracts long-tongued bees, especially bumblebees (Bombus spp.) and Anthophorid bees (Anthophora spp.). Smaller short-tongued bees may visit the flowers, but they are less effective at cross-pollination. The caterpillars of the moth Hemaris diffinis (Snowberry Clearwing) feed on Triosteum spp. (Horse Gentians) and other members of the Honeysuckle family. Sometimes White-Tailed Deer chomp off the upper half of the central stem and its leaves. Photographic Location: An upland oak woodland in McLean County, Illinois. Comments: Late Horse Gentian is easily distinguished from other species of Horse Gentian (Triosteum spp.) by its stem-surrounding opposite leaves (they are connate-perfoliate). Other species in this genus have opposite leaves that taper to narrow bases that are little wider than the central stem. Except for this difference in their leaves, Late Horse Gentian is very similar in appearance to Early Horse Gentian (Triosteum aurantiacum) and they prefer similar habitats. Another species, Triosteum angustifolium (Yellow-Flowered Horse Gentian), has yellow flowers and more narrow leaves; its state distribution is restricted to southern Illinois.
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Miss Chen
2018年06月04日
Miss Chen
Description: This perennial wildflower is 2-4' tall and unbranched. The central stem is light green, terete, and covered with spreading white hairs that are non-glandular. Pairs of opposite leaves occur at intervals along this stem; each pair of leaves rotates 90º from the orientation of the preceding pair of leaves. Each leaf is up to 8" long and 3½" across, narrowly ovate to ovate in shape, and smooth along its margins, tapering to a narrow sessile base. The upper surface of each leaf is dull green to dull reddish green, while its lower surface is whitish green and covered with short fine pubescence. Flowers occur individually in the axils of the leaves. Each flower has a narrow tubular corolla that is reddish brown and about ½-¾" long. The corolla has 5 lobes that are short and well-rounded. The 5 sepals are about the same length as the corolla and linear in shape; they are green to dark reddish brown. At the base of the flower, there is a 3-celled ovary that is green and hairy; there is also a pair bracts that resemble the sepals, except they are smaller in size. The style is about the same length or slightly exerted from the corolla; it has a knobby green stigma. The 5 stamens are hidden with the corolla. The blooming period occurs from late spring to early summer and lasts about 1-2 months. Each flower is replaced by a dry drupe about ½" long that is globoid-ovoid in shape and becomes orange or orange-red at maturity. Inside each drupe, there are 3 black nutlets that are 3-angled and oblongoid in shape. The root system consists of a taproot. This wildflower spreads by reseeding itself. Cultivation: The preference is light shade to dappled sunlight, mesic to slightly dry conditions, and a loamy or rocky soil with abundant organic matter. Range & Habitat: Illinois Horse Gentian is occasional in most areas of the state (see Distribution Map), where it is native. Habitats include upland deciduous woodlands, rocky wooded slopes, and thinly wooded bluffs. Rarely is this species found in prairies. Faunal Associations: The nectar of the flowers attracts long-tongued bees, especially bumblebees (Bombus spp.) and Anthophorid bees (Anthophora spp.). Smaller short-tongued bees may visit the flowers, but they are less effective at cross-pollination. The caterpillars of the moth Hemaris diffinis (Snowberry Clearwing) feed on Triosteum spp. (Horse Gentians) and other members of the Honeysuckle family.
Photographic Location: A wooded slope near Charleston, Illinois. Comments: In spite of the common name, this wildflower is not a gentian (a member of the Gentianaceae); it is more closely related to the honeysuckles. Illinois Horse Gentian differs from the typical variety of Triosteum aurantiacum by the long non-glandular hairs along its stem; the typical variety has some glandular hairs along its stem that are often shorter. Some taxonomic botanists in Illinois consider Illinois Horse Gentian to be a separate species, Triosteum illinoense; however, this reclassification hasn't gained much acceptance from taxonomic botanists outside of the state. Another similar species, Triosteum perfoliatum (Perfoliate Horse Gentian), has opposite leaves that are joined together at the base and surround the stem; the opposite leaves of Illinois Horse Gentian are sessile and remain distinct.
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Miss Chen
2018年05月29日
Miss Chen
Description: This wildflower is a herbaceous perennial about 2-3½' tall that is unbranched. The central stem is light green, rather stout, terete, and glandular-pubescent. Pairs of opposite leaves occur along the entire length of the stem. These leaves are 4-8" long and 1½-3½" across; they are narrowly ovate to ovate in shape and their margins are smooth to slightly undulate. The leaves taper to winged sessile bases; they are not connate-perfoliate (merged together at their bases and surrounding the stem). Upper leaf surfaces are yellowish green to reddish green and glabrous to sparsely short-pubescent, while their lower surfaces are pale or whitish green and densely canescent. Some glandular hairs are usually present on the leaves. Leaf venation is pinnate; networks of secondary veins are prominent on the leaf undersides. Axillary flowers appear at the bases of lower-middle to upper leaves; they are sessile (or nearly so), occurring as either solitary flowers or in small clusters. Each flower is ½-¾" long, consisting of of tubular corolla that is dull red to purplish red, 5 reddish green to reddish purple sepals, an inferior ovary with a single style, and 5 inserted stamens. Along its upper rim, the corolla has 5 short lobes that are rounded and erect. The sepals are about the same length as the corolla; there are linear in shape, short pubescent, and persistent. The style is about the same length as the corolla or slightly longer; it has a swollen green stigma at its tip. The blooming period occurs from late spring to early summer, lasting about 1-2 months. Only a few flowers are in bloom at the same time. Afterwards, the flowers are replaced by 3-celled fruits that become about ½" long at maturity. Mature fruits are orange to orange-red, ovoid-globoid in shape, and glandular-pubescent; their flesh is dry and mealy. Each fruit contains 3 bony seeds that are bluntly 3-angled and oblongoid in shape. The root system consists of a taproot. Cultivation: The preference is light shade to partial sun, mesic to dry-mesic conditions, and soil containing loam, rocky loam, or glacial till with decaying organic matter.
Range & Habitat: The native Early Horse Gentian (Triosteum aurantiacum aurantiacum) is occasional in central and northern Illinois, while in the southern section of the state it is rare or absent (see Distribution Map). Habitats include mesic to upland woodlands, wooded slopes, open woodlands, partially shaded banks of rivers and lakes, thickets, and prairies (including the bases or edges of hill prairies). Occasional wildfires or other disturbance is beneficial when it reduces excessive shade from overhead canopy trees. This wildflower is found in average to high-quality natural areas. Faunal Associations: The flowers are cross-pollinated by long-tongued bees, including bumblebees and Anthophorid bees (Anthophora spp.). These insects mostly suck nectar from the flowers; smaller bees also collect pollen. The caterpillars of a moth, Phyllonorycter mariaeella, feed on Triosteum spp. (Horse Gentians); they are tentiform leaf-miners. Photographic Location: The Coneflower Hill Prairie near Lake Shelbyville in Illinois.
Comments: This is the typical variety of Early Horse Gentian (Triosteum aurantiacum aurantiacum); it is also called Orange-Fruited Horse Gentian. Unlike the similar Illinois Horse Gentian (Triosteum aurantiacum illinoense), Early Horse Gentian has some glandular-pubescence on its stems (not to mention its leaves and fruits). Illinois Horse Gentian differs by having non-glandular hairs on its stems that are somewhat longer (exceeding 0.5 mm. in length). These two varieties are about equally common within the state and they prefer similar habitats. Another native species, Late Horse Gentian (Triosteum perfoliatum), differs by having pairs of opposite leaves that merge together and surround the stem (i.e., they are connate-perfoliate); it is found throughout the state. Yet another native species, Yellow Horse Gentian (Triosteum angustifolium), differs by having yellow flowers and its leaves are more narrow than those of either Early Horse Gentian or Illinois Horse Gentian. Yellow Horse Gentian occurs in southern Illinois, while in the rest of the state it is absent.
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Miss Chen
2018年05月29日
Miss Chen
Description: This herbaceous wildflower is 5-12" tall, consisting of a single stem and a whorl of 3 spreading leaves at its apex. The central stem is purplish green or maroon, terete, glabrous, and rather stout. Individual leaves are 3-4" long and 2-3½" across; they are ovate or oval, smooth along their margins, sessile, glabrous, and parallel-veined. The upper leaf surface is medium green or mottled green (a mixture of both light green and medium green). The leaf bases are rounded and their tips are usually blunt. On a mature plant, a single sessile flower develops on top of the whorl of leaves. Individual flowers consist of 3 dark maroon petals about ¾-1¼" long (rarely greenish yellow or brown), 3 green or purplish green sepals about ½-1" long, 6 stamens about ½-¾" long, and an angular superior ovary with 3 recurved stigmata at its apex. The erect petals are narrowly elliptic to elliptic in shape. The sepals are narrowly lanceolate and widely spreading to slightly ascending; they lie above the plane of the leaves. The anthers have dark maroon and yellow stripes; they are much longer than the filaments. The blooming period occurs from mid- to late spring, lasting about 3 weeks. The flowers usually have a slight aroma of rotting meat. Each flower is replace by a dry 3-celled fruit that is whitish to purplish green. The fruit splits open to release the seeds. The root system consists of a stout rhizome and secondary fibrous roots. Clonal offsets occasionally develop from the rhizome.Distribution Map Cultivation: The preference is dappled sunlight to light shade during the spring; during the summer, more shade is tolerated. The soil should be moist, rich, and loamy with abundant organic matter (decaying leaves, etc.). This wildflower develops slowly from seed, requiring several years to reach maturity. The seeds should be kept moist and planted as soon as possible; they are often slow to germinate. It is also possible to start plants from clonal offsets. Range & Habitat: The native Sessile Trillium is found primarily in NE and southern Illinois, where it is uncommon. It is more common further to the east. Habitats include rich mesic woodlands, floodplain woodlands in valleys, lower slopes of shady ravines, and swamps. These habitats are dominated by such deciduous canopy trees as Sugar Maple, American Beech, American Basswood, and Green Ash. In Illinois, Sessile Trillium occurs in high quality woodlands where the original ground flora is still intact. Faunal Associations: Robertson (1929) observed a small weevil, Centrinites strigicollis, visiting the flowers for pollen. Because of the malodorous odor and color of the petals, the flowers are probably visited by beetles and flies that are attracted to rotting flesh. The polyphagous caterpillars of two moths, Clepsis melaleucana (Black-Patched Clepsis) and Euplexia benesimilis (American Angle Shades), have been observed to feed on trilliums. The seeds are distributed by ants (and possibly some beetles), which are attracted to their elaisomes (food appendages). White-Tailed Deer readily browse on the foliage of trilliums, although Sessile Trillium may be eaten less often than some trillium species because of its dark-colored and less conspicuous flowers. Photographic Location: A soggy area of Goff Woods Nature Preserve in NW Ohio. This woodlands is a small remnant of what was once called the 'Great Black Swamp,' which covered large areas of NW Ohio and NE Indiana.
Comments: In many ways, Sessile Trillium resembles the more common Prairie Trillium (Trillium recurvatum), which is also found in wooded habitats in Illinois. Sessile Trillium can be distinguished from the latter species by its sessile rounded leaves and widely spreading or ascending sepals, which are held above the leaves. In contrast, the leaves of Prairie Trillium taper gradually into petioles and the sepals of its flowers hang downward below the leaves. Both Sessile Trillium and Prairie Trillium can have flowers with greenish yellow petals, but this is rather uncommon. Other trilliums in Illinois have petals that are never colored dark maroon, or their flowers have conspicuous pedicels (flowering stalks). Other common names of Trillium sessile are Toadshade and Wake Robin.
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Miss Chen
2018年05月29日
Miss Chen
Description: This herbaceous perennial plant is about ½–1¼' tall. It consists of a single erect stem that has 3 spreading leaves at its apex. A mature plant produces a single sessile flower above the leaves, while an immature plant produces only leaves. The stem is light green, medium green, or yellowish green; it is terete, glabrous, and fairly stout. The leaves are up to 6" long and 3½" across; they are ovate in shape and smooth along their margins, tapering into distinct petioles. The upper leaf surface is mottled with patches of light and dark green, although sometimes it is solid green. The lower leaf surface is pale green. Both surfaces are glabrous. In addition to parallel primary veins, the leaves also have diagonal secondary veins that crisscross between the primary veins. Each flower consists of 3 yellow petals, 3 green sepals, 6 yellow stamens, and a green ovary with 3 stigmata. The petals are 1–1¼" long, rhombic-elliptic in shape, and erect, curving inward toward their tips. The sepals are ¾-1" long, glabrous, and triangular-lanceolate in shape; they hang downward from the base of the flower. The stamens are about ½" long, curving inward toward their tips; the large anthers of the stamens are narrowly oblongoid in shape and longer than the filaments. The blooming period occurs from mid- to late spring, lasting about 3-4 weeks. There is no noticeable floral scent. Individual flowers are fairly long-lasting. Afterwards, the flowers are replaced by 3-celled fruits (technically berries) that contain many small seeds. These fruits are a little less than ½" in length (about 10 mm.), rhombic-ovoid in shape, 6-angled, and greenish. The seeds are dark brown and partially white from their food appendages. The root system consists of a thickened erect rootstock, secondary fibrous roots, and rhizomes, from which clonal offsets are occasionally produced.
Cultivation: This plant prefers dappled sunlight to medium shade, mesic levels of moisture, and rich loamy soil with decaying leaf litter. Like other Trillium spp. (Trilliums), this species is slow to develop because of the short period of active growth during the spring. The foliage persists until about the middle of summer. Range & Habitat: The native Shay's Trillium is quite rare in Illinois. According to official records, it has been observed in only Jackson County. However, the webmaster encountered it in Champaign County a few years ago, and there has been scattered sitings of Shay's Trillium in northern Illinois (see Distribution Map). Habitats include mesic deciduous woodlands where the original flora has remained little disturbed by modern development.
Faunal Associations: The pollinators of the yellow flowers are unknown. Caterpillars of the polyphagous moths Clepsis melaleucana (Black-patched Clepsis) and Euplexia benesimilis (American Angle Shades) feed on trilliums (Covell, 1984/2005). Because of their food appendages, the seeds are distributed to new locations by ants. White-tailed Deer are very fond of the foliage and flowers of trilliums as a source of food. Their seeds can pass through the digestive tract of these animals and germinate in new locations (Vellend et al., 2003). However, too many deer can cause populations of trilliums to decline because of excessive browsing. Photographic Location: A mesic deciduous woodland at Busey Woods in Urbana, Illinois, and a woodlands in Ogle County, Illinois. The photograph of the Shay's Trillium with mottled leaves was taken by Lisa Culp (Copyright © 2013).
Comments: Shay's Trillium (Trillium recurvatum shayii) is a rare form of the common Prairie Trillium (Trillium recurvatum). The typical form of this species has maroon flowers and black anthers. Another uncommon form of the Prairie Trillium that occurs within the state, Trillium recurvatum lutescens, has yellow flowers like Shay's Trillium, however its anthers are black or purple. In contrast, Shay's Trillium has yellow anthers. All three forms of this trillium usually have leaves that are mottled in different shades of green, however, plants with solid green leaves also occur. Regardless of its form, the Prairie Trillium differs from other trilliums in Illinois by the following set of characteristics: 1) its flowers are sessile, 2) its leaves have petioles, 3) its sepals hang downward, and 4) its petals are yellow or maroon. Other trilliums have flowers on short stalks, or their leaves are sessile, or their sepals are spreading to ascending, or their petals are white.
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Miss Chen
2018年05月29日
Miss Chen
Description: This herbaceous perennial plant is ½-1¼' tall and unbranched. The erect central stem is light green to reddish purple, terete, rather stout, and glabrous. At the apex of this stem, there are 3 spreading leaves surrounding a single sessile flower. Immature plants, however, produce only leaves without the flower. The leaves are 3-6" long and 1½-3½" across; they are ovate in shape and smooth along their margins, tapering into distinct petioles. The upper leaf surface is medium green and heavily mottled with patches of light green and dark green; it is glabrous. The lower leaf surface is pale green and unmottled; it is also glabrous. On rare occasions, some plants will have leaves with solid green upper surfaces. Leaf venation is parallel with occasional interconnecting secondary veins. The flower has 3 maroon petals, 3 green sepals, 6 stamens with long black anthers, and an ovary with 3 stigmata. The petals are 1–1¼" long and rhombic-elliptic in shape; they curve inward toward their tips. The sepals are ¾–1" long, lanceolate-triangular in shape, and smooth along their often purplish margins; they hang downward from the base of the flower. The stamens are about ½" long, curving inward toward the other stamens. The blooming period is mid- to late spring, lasting about 3-4 weeks. Individual flowers are relatively long-lived. There is no noticeable floral scent. Afterwards, each flower is replaced by a single fruit (technically a berry). These fruits are a little less than ½" (10 mm.) long, rhomboid-ovoid in shape, 6-angled, and pale green to purplish green. Each fruit contains several small seeds; they are dark brown with white food appendages. The main rootstock is thickened and elongated, with numerous feeder roots. Rhizomes are also produced, causing this plant to form clonal colonies.
Cultivation: The preference is medium shade to dappled sunlight, moist to dry-mesic conditions, and soil containing loam or clay-loam. The foliage is rarely bothered by pests or disease. Trilliums are slow to develop because of the short period of active growth during the spring, and up to 10 years may be required before a plant reaches flowering size in the wild. Range & Habitat: The native Prairie Trillium is a common plant that occurs in every county of Illinois (see Distribution Map). It is found primarily in rich woodlands, open woodlands, and savannas, where deciduous trees are dominant (including oak-hickory woodlands and maple-dominated woodlands). Sometimes this species survives degradation of woodland habitats, and it can be found along fence rows with woody vegetation, overgrown areas near railroads, and miscellaneous waste areas with partial or light shade.
Faunal Associations: The maroon flowers of the Prairie Trillium may attract carrion beetles and flesh flies, although little is known about the insect pollinators of this trillium (Trillium sp.) because floral visitors are rare. Only pollen is available as a floral reward. The caterpillars of two polyphagous moths, Clepsis melaleucana (Black-patched Clepsis) and Euplexia benesimilis (American Angle Shades) feed on trilliums (Covell, 1984/2005). The seeds of these plants are often distributed by ants because of their food appendages. Among mammalian herbivores, White-tailed Deer are especially known to eat the flowers and foliage of trilliums. There is also some evidence that the seeds of trilliums can pass through their digestive tracts and remain viable. Therefore, White-tailed Deer may help to distribute the seeds across long distances (Vellend et al., 2003). Where White-tailed Deer are too abundant, however, they may destroy local populations of these plants. It is possible that the mottled pattern of the foliage of the Prairie Trillium is an adaptation to deer predation as this type of pattern may help to camoflage the plant with the surrounding forest floor.
Photographic Location: A mesic woodland at Busey Woods in Urbana, Illinois, and an upland savanna in McLean County, Illinois. Comments: The common name is misleading because the Prairie Trillium occurs in woodlands like other trilliums (Trillium spp.), rather than prairies. However, it is especially common in Illinois and the surrounding states where prairies occur. This trillium species is relatively easy to identify for the following reasons: 1) its sepals hang downward from the flower, whereas in other Trillium spp. the sepals are usually spreading to ascending; 2) its flowers are sessile against the central stem and leaves, whereas the flowers of some trilliums (e.g., Trillium erectum) are held above the foliage on short stalks; and 3) the leaves taper gradually at their bases into short petioles, whereas the leaves of some trilliums are sessile and quite rounded at their bases. There are different forms of the Prairie Trillium that have yellow or maroon flowers, yellow or black anthers, and mottled or solid green leaves. The form described here, Trillium recurvatum recurvatum, is by far the most common.
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Miss Chen
2018年05月29日
Miss Chen
Description: This perennial plant is 2½–6" tall and unbranched. It produces a single glabrous stem that terminates in a whorl of 3 leaves. The stem is light green, sometimes with reddish brown tints. The leaves are up to 2½" long; they are green or olive green, oval to ovate, hairless, and smooth along the margins. Their leaf venation is parallel. The base of each leaf is more rounded than its tip; it has a short petiole. Mature plants produce a single flower on a short peduncle about ½" long that is straight or arching (usually the latter). The flower is up to 2" across, consisting of 3 white petals, 3 green sepals, 6 yellow stamens, and a a tripartite style. The petals are oval-ovate and often slightly undulate along their margins. The recurved sepals are lanceolate and often slightly reddish or yellowish on the outer surface. The blooming period occurs during early to mid-spring and lasts about 2 weeks. Each fertilized flower is replaced by a 3-lobed fruit that is about ½" long. The root system consists of a thickened rootstock, secondary feeder roots, and rhizomes. Snow Trillium can reseed itself, but it more often produces vegetative clones from the rhizomes. At favorable sites, colonies are often formed.
Cultivation: The preference is filtered sunlight during the spring (before the trees leaf out), and light shade during the summer. The soil should be mesic to dry, and loamy or rocky with a shallow layer of decaying leaves. There should not be too much competition from other ground layer plants during the late spring or the summer. The foliage withers away by the end of summer. Range & Habitat: The native Snow Trillium occurs in central and northern Illinois, where it is rather uncommon (see Distribution Map). However, it is locally common at a few high quality sites. Habitats include thinly wooded bluffs, upper slopes of bluffs (especially along rivers), and upper banks of rivers. This is an indicator species of high quality woodlands. It grows where the layer of decaying leaves is not too thick.
Faunal Associations: Very few insects visit the early-blooming flowers for nectar or pollen. Most likely, the flowers are pollinated by Andrenid bees (Andrena spp.), queen bumblebees, and other bees that become active early in the spring. The caterpillars of two polyphagous moths, Clepsis melaleucana (Black-Patched Clepsis) and Euplexia benesimilis (American Angle Shades), feed on trilliums (Trillium spp.) occasionally. The fruits are probably eaten by small mammals and birds, although there is a lack of information regarding the particular species that do this. Such animals can help to introduce the seeds into new areas. Deer are very partial to the foliage of trilliums, although the Snow Trillium may be less vulnerable to their browsing than others because of its small size and strong tendency to grow on inaccessible slopes.
Photographic Location: The slope of a bluff in Vermilion County, Illinois, and a river bank at Allerton Park in Piatt County, Illinois. Comments: This is one of the earliest wildflowers to bloom in woodlands and it is the smallest trillium (Trillium sp.). The Snow Trillium can be distinguished from other white-flowered Trilliums by considering the following features: 1) It is only 2-4" tall while in bloom, 2) it blooms earlier in the spring than other trilliums, 3) it has white flowers on a short stalk that is erect or arching, and 4) each fruit has 3 conspicuous lobes. The common name refers to the fact that snow can be found on the ground when the flowers bloom. This cute little trillium should be protected wherever it is found.
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Miss Chen
2018年05月29日
Miss Chen
兰花又名中国兰花、地生兰、兰草,为兰科兰属多年生宿根草本花卉。原产我国其中云、贵、川、藏分布较广,是我国传统名贵花卉,也是世界名花。 人们历来把兰花看作是高贵、典雅的的象征,并与梅、兰、竹、菊合称“四君子”。兰以清香淡雅与菊、水仙、菖蒲并称“花草四雅”,而兰花居四雅之首。兰花朴实无华,叶色常绿,叶质柔中有刚,花幽香清远,有极高的观赏价值,是陈列客厅、居室或点缀书房、门厅之珍品,下面为你详细介绍兰花僵蕾的原因与防治方法。
养兰一年到头也就3个喜悦:春季新苗多多;秋天花苞多多;来年开花多多。但我们却经常会发现有些花苞长着长着就发黑、干缩、脱落了,如何预防兰花僵蕾情况的出现呢? 笔者通过多年的养兰实践观察发现,兰花花芽分化是在新苗的成熟期,要持续近1年的时间。一般兰花经过一年的营养积累,花苞出土。各个品种的花期是不一样的,春兰、蕙兰、墨兰、寒兰、春剑、莲瓣兰等花苞出土后,有一个较长时间的生长、孕蕾和春化过程。这一过程短则五六个月,长的甚至要7个月。四季兰、夏寒兰等从花苞出土到开花,时间不长,短的20来天,长的30天至40天。 无论有春化期还是没有春化期的品种,在营养生长期和生殖生长期都要注意肥水和光照的管理。花苞发黑、焦枯脱落死亡的原因有很多方面,多数是因为湿度过大、肥过多、不通风等原因造成的。一般花芽分化足以说明营养充足,无需继续灌肥,只需叶面追肥就可以了。所谓的花期要注意肥水管理,促使花芽膨大长足,即注意叶面追肥。同时,这一期间温度偏高,兰花仍在继续生长,要加强杀菌消毒。当花苞出土后,若一味施肥、灌水,加之偶遇高温闷热、不通风等情况,就会发生花苞发黑、焦枯脱落死亡的情况。
兰花在孕蕾期,立秋至冬至以前,要加强磷钾肥的追肥,促使花苞膨大长足,不管杀菌消毒还是喷洒薄肥,间隔时间为7天至10天,不能过勤、过浓,适当多见阳光,否则会伤害到花苞导致烂心。另外,要注意开花前的控水、控肥。花苞小的时候,要注意扣水一两次,这与以后的开花品质有直接的关系。如果不是赶时间参加兰展,就不要刻意调节温度和湿度,让其自然开放。 新苗营养生长期要施用以氮肥为主的多元素肥料,促使植株生长壮实,达到抗病、抗旱的目的,保证花芽生长的条件。所以,花苞能不能正常开花,与前期管理密不可分。
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